The invention relates to a carrier roller bearing system of a carrier roller of a roller hearth furnace, that is provided with a first bearing element, that can be attached to the first side panel, and also provided with a second bearing element, that can be attached to the second side panel that lies on the side opposite to the first side panel, a carrier roller bearing that can be rotated and stored in the roller hearth furnace with its first longitudinal end by means of the first bearing element and with its second longitudinal end by means of the second bearing element, whereby a shaft journal extends or protrudes externally towards the outside from the first bearing element, which can be connected for drive purposes with a driving unit.
Furthermore the invention relates to a carrier roller handling system for switching a carrier roller of a roller hearth furnace that is provided with a base support, a pivot support that is attached to the base support and a first roller handling system, that is attached to the pivot support and can lift or raise a carrier roller.
Finally the invention relates to a process for switching or exchanging carrier rollers of a roller hearth furnace that is provided with a carrier roller bearing system, by means of a carrier roller handling system, in which the carrier roller bearing system is driven sideways near the roller hearth furnace to the position of the carrier bearing that is to be dismantled or dismounted, the shaft journal of the roller bearing that is to be dismounted is decoupled, then the carrier roller handling system is backed up to the carrier roller that is to be dismounted and then a fastener or fixation of the first bearing element is disengaged or detached from the roller hearth furnace.
A carrier roller bearing system of the type identified at the outset is for example known from the patent DE 10 2011 079 771 A1, from which a carrier roller handling system as well as the process of the type identified at the outset are to be learnt.
Roller hearth furnaces, which are also known as continuous furnaces and are used for example in continuous annealing or homogenization plants, use a number of carrier or conveyor rollers that transport the items or piece goods that are to be heat-treated through the roller hearth furnace. While heat treating steel materials in the temperature range of around 800° C., the upper surfaces of the roller bearings tilt to enable the formation of irregular, firm coatings, which are difficult to remove. While doing so, with the increasing thickness of the coating on the surface of the carrier rollers grows the risk, that the irregularities get imprinted on the steel and leave undesired patters on the items or product that can especially lead to product defects in the following manufacturing process. The operators of these kinds of plants with roller hearth furnaces are hence compelled to interrupt the oven operation for carrying out expensive cleaning measures repeatedly and for longer times. However a defect in one carrier roller so far led to the entire oven needing to be shut down and cooled, in order to replace the defective roller bearing with a new roller bearing. Such a replacement of roller bearings can for example last for one or more days, something which involves a significant loss of production.
The patent DE 10 2011 079 771 A1 does not provide any design engineering details regarding the manner in which a replacement of roller bearings can be realized as efficiently as possible; but rather a concept, according to which a roller bearing exchange can be implemented by means of a roller bearing handling device that is moveable on the side near the roller hearth oven and it drives a lance into the hollow roller bearing that needs to be changed and lifts this roller bearing out of the oven. Such concepts that implement the roller bearing change by means of especially designed and constructed devices that are arranged laterally near the roller heath furnace, are however known from prior art. For example the document DE 40 41 217 A1 describes a continuous oven, in which the roller bearings that are driven are made of liquid cooled core pipes and the core pipes are provided with heat insulating systems. In this continuous oven, only the heat insulating systems are replaced. The core pipes remain inside the oven during the change. In this, a pulling-out and inserting device pulls the insulating system laterally out of the oven and subsequently inserts a new insulating system over the core pipes that are arranged in the oven as before. In both cases, the exchange of a roller bearing is however associated with significant operational interruptions and consequently with losses of production.